SF3B1 and myelodysplastic syndrome: To assess whether targeted UBA1 inhibition through TAK-243 in primary HSPCs from MDS patients would selectively reduce SF3B1-mutant cells, as observed with K562 cells, we performed CFU assays with CD34+ BM MNCs from sex-matched SF3B1-mutated MDS patients and healthy donors (Fig. 5G).